Automatic air valve



March 1 1 R. M. -TEEGARDIN AUTOMATIC AIR VALVE Filed Oct. 5, 1920 a? um 11 foz /7 Bayard/)1 I Patented lit/liar. ill 1924i.)

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AUTOMATIC AIR VALVE.

Application filed October 5, 1920. Serial No. 414,888.

To all whom it may concern:

Be it known that I, ROBERT M. TEEGARDIN, a citizen of the United States, residing at Seattle, in the county of King and State of Washington, have invented a certain new and useful Automatic Air Valve, of which the following is a specification.

My invention relatesto an automatic air valve and more particularly to an air valve for use in the train line of a railroad car to prevent collisions when a break-in-two occurs in a train of cars.

At the present time in railroad operation many collisions follow upon the trains breaking in two. The brakes on the cars are adjusted to a standard so that a substantially uniform pressure is exerted upon the brake shoes by the breaking levers of each car of the trainsaid breaking levers being compressed air operated. This adjustment is expressly designed to render it impossibleto lock the wheels against turning, that is,

impossible to slide or pickup the wheels,

as it is commonly known. Hence, it is usual to adjust freight car brakes so asto break about 70% of the light car load, (this figure varies) and hence the'car wheels are not picked up,with the result of flattening them. The damage of breaking a rail from a flat wheel, which has been determined to give a blow often amounting to several tons to each revolution, is well known.

The safety margin of 30% is designed also to prevent sliding or picking up the wheels due to a lack of traction, as when frosty or wet. Thus, it is manifest, that no provision is made for braking the load carried by the car and the effectiveness of the brake adjusted as it is ordinarily for 70% of the light car load, is therefore greatly re.

' duced.

From this it is clear that when a train breaks in two and there are fewer cars in the front than in the'rear portion that the front part will come to a stop first since the momentum of the rear is greater than that of the front portion and the result is that the rear jams or collides with the front portion often causing great damage and even loss of life.

It will be understood that a train, as commonly equipped at the present time, has a regular train compressed air line extending from one end of the train to the other. This line is closed at the rear end. The train line supplies the auxiliary air tanks local to each car and connected with the brake cylinders which are equipped with with a piston which in turn is connected by various intermediate means to the brake shoes. The pressure in the train line is essential to keep the brakes from setting. Hence when there is a break in the train, ordinarily there is a break in the train line. Considering the front or engine portion of the train composed, we will assume of five cars as opposed to twenty five cars for the rear portion, the air rushes out of the open end of the broken train line and the air pressure drops, which promptly sets the brakes and brings this. part of the train to a standstill. Now, considering the rear portion of the train; here the brakes are likewise set but since this portion of the train has so many more .cars than the front part, it has a much greater momentum and hence is not stopped as quickly as the front portionthe small breaking power of the brakes having been hereinabove set forth.

The momentum thus causes it to collide with the front portion.

The objects of my invention are: To provide an automatic air valve which will prevent such collision when a bneak-in-two occurs in a train line which will not interrupt the normal operation of said air line, but in the event of an accidental break in said air line, either in front or in the rear of said valve, will function automatically to allow the reduction of the air pressure in said air line at a predetermined rate.

Respecting the application of my device in general, it will be understood that each car of the train, in its train line, is equipped with an automatic valve embodying my invention. So long as the train remains intact, the valve herein set forth does not operate, the pres-, sure of said air line belng free to operate through said valve. However, so soon as a break in the train line occurs, my valve oper ates to prevent the sudden escape of the air and consequently the sudden application of the brakes. In this wise, the front or engine part of the break-in-two train is assured of not having its brakes applied be fore the rear part, since the engine part can draw on the source of supply of air pressure to maintam the requislte train hne prestoo sure which functions to keep the brakes from setting. The air valve embodying my invention in the first car behind the break-in-two part. also operates to prevent the sudden application of the brakes, but as there is pro-' vided a gradual escape of the air and since the only pressure, in this rear part of the train, crating to prevent the setting of the brakes, 1s that which is trapped upon the moment of the accident to the train line, this part of the train'is definitely destined to come to a stop prior to the front part which has the engine source of supply to augmentthe pressure which is trapped in that part of the train pipe line. From this it will appear that such a valve at all times must be capable of operating in either direction, depending upon which side the break occurs and the operation of such a valve must provide for the uninterrupted communication between that part of the train line in which there is numerals indicate like Fig 1.

(valve casing 4, encloses the valve parts and may be composed of the middle or barrel portion 5, to the-ends of which reducers 6 and 7 may be secured. These reducers screw on to the end portions 8 and 9 of a train line. The barrel portion 5 of the casing en-' closes the valve chamber 10. Valve seat members 11 and 12 fit snugl in the said reducers with which they may integrally formed. Within these seat members are slidably disposed valve members 13 and 14, having large conduits 15 and 16 and ports 17 and 18. These ports are closed when the valve members are moved so that the valve seat portions 19 and 20 of the valve members contact with the similar seat ortions 21 and 22 carried by the seat mem ers 11 and 12. Recesses 23 and 24 are preferably provided between thevalve seat members 11 and 12 and the said valve members 13 and 14, in which recesses springs 25 and 26 function to keep the said valve members in 0 en position, i. e. so that the conduits 15 an 16 communicate through ports 17 and 18 with the valve chamber 10. Relatively small air conduits 27 and 28 in the valve members form a means of direct communication between chamber 10 and the conduits 15 and 16. A rod 29 connects the valve members so that they move together. Aport 30 in the bar justment is dispensed with. The conduits 27 and 28 are joined in the modified form to constitute the single conduit 32 from which conduit 33 may extend laterally.

The operation of my device is as followsi I Under normal operation, the valve functions as a conduit, 1. e. as apart of the regular' train line. The air pressure in the valve chamber being equal on all sides of the valve members, they remain in open position as shown in Figure 1. Assuming then the engine part of the train (each car of which is equipped with a valve embodying my invention) is to the left of this valve, the pressure passes from the train line 8, through the conduit 15, port '17, into valve chamber 10, through port 18, and conduit 16 to pipe line 9. Part of the air pressure finds 1ts Way simultaneously through conduits 27 and 28.

However, when a break in the train line occurs (we will assume such break occurs to the right of the valve illustrated) the air rushes out to the right and the unbalanced pressure, bearing upon the head of the valve member 14, closes said member. Thereafter, the air pressure is reduced only by such amount as escapes through the small leakage conduit 28. The amount thus escaping is re-supplied to the line from the engine and the brakes on this engine art of the breakinetwo train are prevente from setting On the rear part of the train, the valve on the car next to the broken train line is closed as respects the valve member 13, since in this part of the train, the air will rush to the leftjust opposite to that of the engine part of the train. And here also the air will gradually escape through conduit 27 so that the brakes on this rear part will be set graduall that all inju stopping will avoided. Manifestly, there is no supply of pressure in this rear part operating to replace that which is lost through conduit 27 as in the case of the front or engine part of thetrain. The 'engine part of the train is kept running until it is manifest that the rear part is brought to a stop and all danger of a collision is avoided.

Frofn the above, the operation of the modified form of my air valve will be readil understood. The conduit 33 is not essentia since the auxiliary tank line 31 is amply supplied with air pressure'from the chamber 10.

Obviously, changes may be made in the forms, dimensions, and arrangement of the and not suddenly, so to t e cars from asudden parts of my invention, without departing from the principle thereof, the above setting forth only a preferred form of embodiment.

I claim:

1. An automatic air valve embodying a valve casing, a valve chamber having a port in each end thereof, said ports being disposed to function either as an inlet or outlet port as circumstances may require, a double valve member slidably disposed in said chamber, and means to maintain normally said valve in open position.

2. An automatic air valve embodying a valve casing, a valve chamber, a double valve member slidably'disposed in said chamber, said valve member having an air conduit therethrough, and a spring connected to said valve member.

3 A train. line valve embodying a valve casing, an auxiliary reservoir port in said casing, a valve chamber,.a double valve member, slidably disposed in said chamber, said valve member having an air conduit therethrough; and a spring connected to said valve member.

4. An automatic air valve embodying a valve casing, a valve chamber, a double valve member slidably disposed in said chamber, air conduits on each side'of said valve member, an air conduit through said valve member relatively small as compared to said first mentioned conduits, and means to maintain normally said valve in open position.

5. An automatic air valve embodying a valve casing, a valve chamber having a port in each end thereof, said ports being disposed to function either as an inlet or outlet port as circumstances may require, a'

valve casing, a valve chamber having a port in each end thereof, said ports being disosed to function either as an inlet or outet port as circumstances may require, a double valve member slidably disposed in said chamber,air conduits on eachside of said valve member, an air conduit through said valve member relatively small as compared to said first mentioned conduits, an auxiliary port disposed at all times in open communication with said valve chamber, and means to maintain normally said valve in open position.

In witness whereof, I hereunto subscribe my name this 11th day of September, 1920.

' ROBERT TEEGARDIN. 

